Monohaloalkanes Flashcards
How are monohaloalkanes classified?
They are categorised as primary, secondary, or tertiary based on the number of alkyl groups attached to the carbon atom holding the halogen.
What defines monohaloalkanes?
Compounds containing only one halogen atom.
What reactions do monohaloalkanes participate in with strong bases like potassium or sodium hydroxide in ethanol?
Elimination reactions, resulting in the formation of alkenes.
Name one product of the nucleophilic substitution reaction involving monohaloalkanes and aqueous alkalis.
Alcohols.
What product is formed when monohaloalkanes react with alcoholic alkoxides?
Ethers.
How do monohaloalkanes react with ethanolic cyanide, and what product is formed?
They form nitriles, which can be hydrolysed into carboxylic acids, essentially increasing the chain length by one carbon atom.
What are the two mechanisms by which a monohaloalkane can participate in nucleophilic substitution reactions?
SN1 and SN2
Describe the SN1 mechanism.
It’s a nucleophilic substitution reaction with one species in the rate-determining step, occurring in a minimum of two steps via a trigonal planar carbocation intermediate.
Explain the SN2 mechanism.
It’s a nucleophilic substitution reaction with two species in the rate-determining step, occurring in a single step via a single five-centered, trigonal bipyramidal transition state.
How are the reaction mechanisms for SN1 and SN2 reactions typically represented?
Using curly arrows.
What factors can determine which mechanism (SN1 or SN2) will be preferred for a given haloalkane?
Factors such as steric hindrance and the inductive stabilisation of the carbocation intermediate.
what is steric hindrance?
the resistance encountered by molecules when they approach each other closely due to the presence of bulky groups or atoms.
